Thursday, June 24, 2010

Coal burning cars

kw: opinion, technology, environmentalism

In the July 2010 issue of Scientific American, Michael Moyer has written an article that speaks directly to a concern I have long had about electric cars: Where does the electricity come from? The article, on pages 55-56, is titled "The Dirty Truth about Plug-in Hybrids".

To cut to the chase, the amount of benefit, or lack thereof, simply depends on where you live. A plug-in hybrid vehicle is expected to use about half the gasoline used by a first-generation hybrid such as the Toyota Prius or a Honda Civic Hybrid. An all-electric car, of course, burns no gasoline at all. Thus, in most parts of the U.S., an all-electric uses no gasoline, but not all. In New York state, in particular, where 2/3 of the electricity is generated by burning petroleum products similar to gasoline, you may as well be driving a gasoline-burning car.

In most of the rest of the highly-populated, industrial Northeast and in the deep South and upper Midwest, while little or no electricity is generated using petroleum, from half to 75% is generated using coal, making an electric vehicle that plugs in a worse producer of carbon dioxide than a pure hybrid vehicle.

The areas where an electric, whether all-electric or plug-in hybrid, will have a benefit in both reducing carbon dioxide and greatly reducing petroleum consumption are those areas that use no petroleum or coal to generate electricity: the Pacific Northwest, California, Texas, and Florida. In the lower Midwest and desert Southwest and New England, though a little coal is used, little enough is burned that an electric car is also a benefit there.

Now consider population. The coal-burning areas are mostly high-population areas, and the natural gas-burning (and nuclear-powered) areas are mostly areas of lower population density. The only highly-populated area in which an electric car is a distinct benefit is California.

If you are considering getting a greener car, find out where your electricity comes from. If you are in a coal-burning area, a pure hybrid is probably the best. Otherwise, a "more electric" vehicle just may be the right thing to get.